Although it is the responsibility of the motorist to check before opening their door, riding too close to parked cars (in the door zone) is still a common mistake bicyclists make that can lead to serious injury. For more information on this type of bicycle facility, visit the Sharrows FAQ.
triangle. n. 1. (Mathematics) geometry a three-sided polygon that can be classified by angle, as in an acute triangle, or by side, as in an equilateral triangle. Sum of interior angles: 180Â°; area: base Ã height. 2. any object shaped like a triangle. 3. any situation involving three parties or points of view. See also eternal triangle. 4. (Instruments) music a percussion instrument consisting of a sonorous metal bar bent into a triangular shape, beaten with a metal stick.
Noun[edit] ( 1 geometry) A triangle having at least two sides equal.  Usage notes[edit] In original usage, an isosceles triangle was understood to have the third side unequal to the other two, that is, an isosceles triangle has exactly two equal sides. An equilateral triangle is, however, a special case of an isosceles triangle, having all three sided equal. Of trilateral figures, an equilateral triangle is that which has its three sides equal, an isosceles triangle that which has two of its sides alone equal, and a scalene triangle that which has its three sides unequal.